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In debate

Are clouds green?

Clouds are often referred to as a ‘green technology’ because they could better utilise computing resources. But this is not necessarily the case.

Cloud data centres can be greener than corporate IT. However the difference between data centre efficiency and its overall environmental effect must be recognised.

By outsourcing to the cloud, researchers or businesses are not cutting down their energy use; they’re just moving it off-site. And calculating the difference in energy between using a data centre in the cloud or on site-resources is far from easy.

Data centres are built to deal with the constant stream of information we produce, so centres therefore consume exponential amounts of power, creating vast amounts of pollution.

Big companies such as Microsoft and Accenture have argued that data centres have lots of benefits. They state that public cloud computing environments can cut energy consumption and carbon emissions by 30% compared to an organisation that runs the same software on its own infrastructure.

In addition, data centres provide cloud computing efficiencies that other organisations could not achieve, such as:

- reduce over-allocating of infrastructure for peak times (Dynamic provisioning)
- share application instances between multiple organisations (Multi tenancy)
- operate server infrastructure at a greater percentage of the time
- improve data centre efficiency

With multi-tenancy, thousands of companies may run applications in one cloud computing environment. Amazon was the first group to make great efficiencies on its servers that are hard to match by a company operating its own server environment. Microsoft and Google followed suit having since made continuous improvements in optimising data centres.

With such improvements and optimisation, it seems obvious that shared data centres would save more energy than a corporate IT department. However data centres are being built in record numbers, consuming extensive amounts of energy. It has been estimated that the energy consumption of cloud computing will triple by 2020 if energy solutions are not applied.